1. Field of Invention
Embodiments of the invention relate generally to a communications system and method, and more particularly, specific embodiments are directed to a method and system for identifying individual modules or devices.
2. Discussion of Related Art
In a typical system that employs a communications bus to communicate between individual devices or modules of the system, it is necessary to assign addresses to the devices to allow each device to be identified by a master controller and/or other devices, so that messages and commands can be addressed to each device, and so that the source of messages and commands can be identified. In prior systems, a number of schemes exist for setting an identifier or address for each device. In one such prior art system, each module or device has a number of additional digital inputs in a communications bus connector that are used to set an address of the device. Each input can be set, for example, “high” or “low” to set an address for the device. One problem with such a system is that the number of digital inputs required increases as the number of devices in the system increases. For example, in a system having 32 devices, to provide a unique address for each device typically requires 5 digital inputs as the number of unique addresses is equal to 2n, where n is equal to the number of digital inputs. Another problem with this solution is that the procedure for setting each input high or low is to solder short circuits between appropriate pins of a mating connector. This process can be labor intensive and prone to errors.
In another known system, dipswitches or jumpers are used to set the address of each device in the system. This approach is simple and relatively inexpensive, but requires as many digital inputs as the system described above, and requires the manual setting of dipswitches or jumpers during an installation or manufacturing operation and can be prone to errors.